SectionProperties update update

Posted on 26/01/2022 by dougaj4

Since my previous post on the Python SectionProperties program it has been updated to Rel. 2.02, with some major changes:

  • The mesh generation library has been changed from MeshPY to Triangle
  • New functions have been added for:
  • Steel sections
  • Concrete sections (including reinforcement)
  • Australian precast bridge girders (Super T and I sections)

My spreadsheet has been updated to work with the new version, and can be downloaded (including associated Python code) from:

py_SectProp2_02.zip

The problems with installing the SectionProperties software on Windows have now been fixed, and installing with pip also installs the new Triangle library. The software required to run the spreadsheet (in addition to the download files) is now:

  • Python 3.9 and associated code, including Numpy and Matplotlib.
  • Pyxll
  • Section-Properties 2.02 (install with pip to also install Triangle)

Example screenshots from the new spreadsheet are shown below:

Setting the “out” argument to 11 will now display the cross section with the generated mesh:

The defined sections have now been reduced in number to 6:

… but there are now 14 steel sections that can be accessed with the getSteelSect function:

There is also a new getConcretesect function, including reinforcement:

New functions that will generate Australian precast bridge girder cross sections are SuperT:

… and IGirder:

Posted in Concrete, Excel, Finite Element Analysis, Link to Python, Newton, PyXLL, Strand7 | Tagged , , , , | 2 Comments

Danny Thompson by The Music Aficionado

Posted on 25/01/2022 by dougaj4

I just discovered The Music Aficionado site, where Parts 1 and 2 of a series on the life and times of Danny Thompson have recently been posted:

I have been toying with the idea of writing an article about Danny Thompson for a while. His playing is a common thread across so many albums I cherish, that dedicating an artist profile article to him seemed inevitable. But where to begin, what to cover? There are over 400 album credits with his name on it, spanning almost six(!) decades. The task seemed monumental, given my inability to avoid digging deep into my chosen subjects. I finally decided to take the plunge and go for it. So here is the first article in a series (what else?) that will cover a few decades of his unique career. This one here is dedicated to his work in the 1960s.

The articles are detailed and very well written with many stories and YouTube links that I had not seen before (and many others I was happy to listen to again). See the articles at:

Danny Thompson: Part 1, The 1960s

Danny Thompson: Part 2, The Early 1970s

… and a couple of sample YouTubes (many more at the links above):

Davy Graham with Danny Thompson – Joni Mitchell’s Both Sides Now
Pentangle – Live performance from 1968
Posted in Bach | Tagged , , , | Leave a comment

Embedding OneDrive in WordPress

Posted on 23/01/2022 by dougaj4

Every time I try to add a new link to a file on OneDrive in WordPress, it seems they have changed the system to stop it working.  After much trial and error, the procedure given below works, for now.

  1. Open the file in OneDrive on-line, and select File-Share-Embed:Embed1

2. Select the desired display options, then click on the “Embed code” box, and copy the code to the clipboard:

3. Return to the WordPress editor, click on the Options menu (top-right) and select Code Editor, then just paste the code generated in Excel:

You can then return to the Visual editor, and save the post complete with embedded spreadsheet.

Posted in Excel, Newton | Tagged , | Leave a comment

Publications

Posted on 23/01/2022 by dougaj4

I have recently updated my list of publications. Click on the “view full-size” icon in the bottom right corner for a full screen view, or click any link to download.

Posted in Concrete, Geotechnical Engineering, Newton, Strand7 | Tagged , , | 4 Comments

SectionProperties update

Posted on 16/01/2022 by dougaj4

In late 2017 I posted Section Properties with MeshPY, including torsion and warping which looked at an Excel front end for Robbie van Leeuwen’s SectionProperties program, which provides facilities for calculation of section properties of complex shapes, including torsion and warping constants. Since then the development has moved to Github and there have been many updates to the code. I have now revised my spreadsheet and Python code to work with the latest version (1.08) and Python 3, using pyxll to link to the SectionProperties Python code:

pySectProp1_08.zip

As well as the spreadsheet and Python code in the download zip file, the following code is required to be installed:

With Windows 10 and Python 3.9 I found that Meshpy installed with pip with no problems, but installing Section-Properties with pip raised repeated errors. However simply downloading the code from GitHub, then copying the top level “sectionproperties” folder to my active pyxll code folder worked with no problems. (Update: installing with pip now works well, see SectionProperties update update)

The Excel spreadsheet provides access to the numerical section properties output for any of the 18 pre-defined shapes, or any custom shape. At this stage the graphical output is limited to plots of the geometry of the shapes. The next version of Section-Properties will be switching from Meshpy to the Triangle library for generation of the section meshes, and when that is released I will look at extending the plotting functionality in the spreadsheet.

The screenshots below show examples of the output with the current code:

The first example is taken from the Section-Properties docs, with a hard-coded circular shape of diameter 50, divided into 64 segments. The results are compared with results from the Strand7 FEA package with the same shape:

The next example reads the section “points” and “facets” from the spreadsheet, and divides the shape into two regions, with different specified mesh-sizes:

The next sheet generates a shape from an Eng-Tips discussion:

The calculated section properties are compared with values from a Strand7 analysis, with very close agreement:

The Defined_Shapes sheet lists the 18 defined shapes, and uses the GetSect function to generate the section properties for a named shape. The full output list 64 properties, or an array of row numbers may be input to list the selected properties:

The cross-section graphic is generated with the same function, setting the final “out” argument to 10:

Posted in Charts, Excel, Finite Element Analysis, Link to Python, Newton, Numerical integration, NumPy and SciPy, PyXLL, Strand7 | Tagged , , , , | 1 Comment